We study how couples allocate retirement-saving contributions across each spouse's account. In a new dataset covering over a million US individuals, we find retirement contributions are not allocated to the account with the highest employer match rate. This lack of coordination—which goes against the assumptions of most models of household decision-making—is common, costly, persistent over time, and cannot be explained by inertia, auto-enrollment, or simple heuristics. Complementing the administrative evidence with an online survey, we find that inefficient allocations reflect both financial mistakes as well as deliberate choices, especially when trust and commitment inside the households are weak.
Pareto Efficiency is a core assumption of most models of household decision-making. We test this assumption using a new dataset covering the retirement saving contributions of over a million U.S. individuals. While a vast literature has failed to reject household efficiency in developed countries, we find evidence of widespread inefficiency in our setting: retirement contributions are not allocated to the account of the spouse with the highest employer match rate. This lack of coordination cannot be explained by inertia, auto-enrollment, or simple heuristics. Instead, we find that indicators of weaker marital commitment correlate with the incidence of inefficient allocations.